http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49653
--- Comment #7 from Gary Funck <gary at intrepid dot com> 2011-07-07 16:38:33 UTC --- (In reply to comment #6) > why not just add this to make the code valid by emitting an extern definition? > > extern long trouble(long, long); If you're suggesting that the front-end would do this automatically when compiling -O0 -std={gnu}99, I'd agree that this would be a good way to handle this use case.